"Please! Embrace technology," says Wojcicki, photographed at YouTube's San Bruno, California, headquarters. "It helps you understand the world around you."

Susan Wojcicki always knew she wanted two things in life: to have four kids and "to do something meaningful, something really different." But Wojcicki, 45, found that "something really different" almost by accident. In 1998, she and her new husband, Dennis Troper, rented their garage to two Ph.D. students who were trying to create an easy way to search the then unwieldy Internet. "What they were doing sounded so exciting, and I wanted to be a part of it," says Wojcicki. So at four months pregnant, she quit her job at computer-chip maker Intel and joined Sergey Brin and Larry Page as their marketing manager and employee number 16. It was a bold move but a good one: That company was Google.

By 2014 Wojcicki had helped grow that little start-up into a $400 billion juggernaut, with more than 45,000 employees. Along the way she had those four kids—and juggled it all around a golden priority: Be home for family dinner at 6:00 P.M., every night. "Susan is not only a great executive," says one of her former colleagues, Sheryl Sandberg, the chief operating officer of Facebook and author of Lean In, "but a great friend to me and many women. She offered valuable guidance." Wojcicki's advice to any working woman thinking of starting a family? "Don't forget that it gets easier! Having a child is a big life change, but the really hectic period is relatively short," she says. "You can get through it."

Impressive career? You bet. But that was just the beginning. This February, Wojcicki became CEO of YouTube, a company she helped Google purchase back in 2006 for $1.65 billion (it's estimated to be worth up to 10 times that today). Not only does the gig make Wojcicki one of just six women CEOs at the top 100 tech companies in the United States, it also puts her in the position to do what she's most passionate about: help women achieve their dreams. "On YouTube women are not just users; they're creators," she says. "They're learning about business and technology, and having a voice." And they don't have to wait for a record label or movie company to give them permission. With one billion unique monthly visitors, the site has become a clearinghouse for young talent, making household names out of everyone from Michelle Phan to Kandee Johnson. It's a new generation of talent, and Wojcicki couldn't be more excited to usher them in: "I'm happiest," she says, "when I see the future."

Her words to live by: "Don't overplan your life. Joining Google when I was four months pregnant was a bit of a leap, but sometimes you have to do the right thing for you right now."